“It’s like you’ve got to put a mirror under his nose to check if he’s breathing, he’s so calm, cool and relaxed,” leadoff man Matt Carpenter said after Beltran delivered another big October performance in a 3-2, 13-inning victory over the Los Angeles Dodgers on Friday night.

“It’s like jazz music is playing in his head. He’s just so even-keel, nothing gets to him.”

Beltran hit a tying, two-run double in the third inning. Then he took charge on defense, calling center fielder Jon Jay off the ball before throwing out a runner at the plate from shallow right field in the 10th to keep it even.

“I felt I was going to have a better angle so I called for the ball about five or six times,” Beltran said. “And Jon Jay was able to hear me and leave it up to me.”

Well past midnight at Busch Stadium, but with most of a sellout crowd still waiting expectantly, Beltran singled into the right-field corner with one out against Kenley Jansen to finish a game that took 4 hours, 47 minutes.

Neither team had much time to exhale before Game 2 Saturday afternoon, scheduled to start 14½ hours after Daniel Descalso crossed the plate. It features a marquee pitching matchup — major league ERA leader Clayton Kershaw vs. Cardinals rookie Michael Wacha, who’s flirted with no-hitters his last two starts.

“If the rest of this series is like this game,” Dodgers manager Don Mattingly said, “it should be a pretty good one.”

Beltran has 16 home runs, 12 doubles and 34 RBIs in 40 career postseason games, and is hitting .345. He’s also scored 42 runs and stolen 11 bases while with the Astros, Mets and Cardinals.

The eight-time All-Star is hoping this year ends with his first trip to the World Series.

It was the longest postseason game for the Dodgers since the 1916 World Series, when Babe Ruth pitched all 14 innings to lead the Boston Red Sox past Brooklyn.

This one also tied for the longest series opener in postseason history, according to STATS. Boston and Cleveland played 13 innings in their 1995 AL division series, with the Indians winning 5-4.

“You work so hard in the offseason, spring training and regular season to get to this point and we’re fortunate to be here,” Beltran said. “That’s a preview. Today was a good game and that’s it’s all about.”

Descalso had a pinch-hit single with one out in the 13th off rookie Chris Withrow, and Matt Carpenter walked. Jansen, usually the Dodgers‘ closer, relieved and Beltran won it with his hit on a 3-1 count.

The Cardinals are unbeaten in extra-inning postseason games since dropping the opener of the 1946 World Series to Boston. That said, they’re just 4-0 in that span.

Winning pitcher Lance Lynn strengthened his case for a possible Game 4 start with two scoreless innings. Withrow took the loss.

The Dodgers had two on in the ninth, 10th and 11th and came up empty. They stranded 11 overall while going 1 for 10 with runners in scoring position. They averaged 6½ runs and batted .333, best ever in an NL postseason series, while taking a four-game division series from the Braves.

Dodgers starter Zack Greinke struck out 10 in eight innings, allowing just four hits. Cardinals starter Joe Kelly left after the sixth with the score 2-all.

Mark Ellis tripled with one out in the Dodgers‘ 10th. After Hanley Ramirez was intentionally walked, Michael Young followed with a fly ball to shallow right field that Beltran caught.

Beltran made a strong, one-hop throw home and Ellis crashed into Gold Glove catcher Yadier Molina.

Molina held the ball, but it was hard to tell whether he actually tagged Ellis. On such plays, however, umpires almost always give the benefit to the catcher and call the runner out.

“You’ve got to go, that’s what you do,” Ellis said. “They made a great throw, Yadi made a great tag.”

The Dodgers put runners at first and second with two outs in the 11th against John Axford. Pinch-hitter Nick Punto, who played for the Cardinals on their 2011 World Series championship team, struck out to end the inning.

Young, in the game after cleanup man Adrian Gonzalez was pulled for a pinch-runner in the eighth, got another chance in 12th. With runners on first and second, he grounded into an inning-ending double play against Lynn.

Slowed by a sore ankle, Ethier made his first start in this postseason. He appeared to mistime his jump just a bit as he banged into the padded wall.

Beltran’s two-run double in the third was the only damage against Greinke. He fanned Carpenter, Matt Adams and Pete Kozma twice each and struck out the side in the fifth.

The teams are postseason foes for the first time since a Dodgers sweep in their 2009 division series. It’s their first NLCS matchup since 1985, when the Cardinals won in six games behind game-breaking homers from Ozzie Smith and Jack Clark off Tom Niedenfuer.

Kelly left on his own terms after six innings in a 2-all tie, hurt only by Juan Uribe’s two-run single in the third. Counting multiple efforts, the Cardinals had five relievers warm but the Dodgers were 1 for 7 with runners in scoring position.

Kelly got all three outs on strikeouts in the first. The Dodgers left runners on second and third when Gonzalez and Yasiel Puig fanned.

Kershaw started the division series clincher against Atlanta on three days’ rest Monday and will be on regular rest in Game 2. The left-hander said the media made a big deal of short rest, but not he nor Mattingly.

Dodgers hitting coach Mark McGwire got a nice hand when he lined up along the third base line during introductions. So did two other former Cardinals, utility men Skip Schumaker and Punto. There was some booing for Greinke, who referred to Cardinals ace Chris Carpenter as a “phony” when Greinke was with the Brewers.